Cancers of the prostate and breast constitute almost one-third of all cancers in the United States. These neoplasms, which have been characterized as hormonally-linked, are the leading cancers in American men and women. Despite obvious gender differences, these cancers share a substantial common ground [eg. similar rates of incidence, parallel epidemiologic relationships to various factors (high fat diet, obesity, etc.) and analogous proposed pathways of etiopathogenesis]. An academic award is sought in efforts to broaden the applicant's understanding of these hormone-related cancers. This effort is sponsored by primary mentor Barbara Rimer, Dr.PH, with planned experiences in relevant programs directed by James Iglehart, M.D., Eric Winer, M.D., Claude Hughes, M.D., Ph.D., and Cary Robertson, M.D. of Duke, and University of North Carolina's Paul Godley, M.D., Ph.D. and Boyd Switzer, Ph.D. The ultimate goal of the proposed program is to provide the applicant with a working knowledge-base in prostate and breast cancer, endocrinology and molecular biology/genetic regulation - a knowledge base that would complement her skills as a nutritionist and enable her to identify appropriate intermediate end points for nutrition intervention in these areas. This training will afford the applicant the springboard necessary for translational research in these areas and the opportunity to become an independent investigator in preventive oncology. A research project is a focal piece of the proposed training, and will permit the investigator to broaden and continue her interest in diet, body fat and its distribution, and their relationship to the continuum of neoplastic disease. The study is entitled "Exploration and Intervention in Weight Gain Associated with Adjuvant Chemotherapy for Breast Cancer." Weight gain is a common side effect in women receiving adjuvant chemotherapy for breast cancer - one that has been consistently reported throughout the past twenty years. For some therapies, gains of over 22 pounds are seen in one out of four women. This weight gain may be undesirable. First, it may have a profoundly negative psychosocial impact on a group of patients who may already have a compromised sense of self esteem. Second, recent findings suggest that weight gain during therapy is associated with decreased survival. Although weight gain during adjuvant chemotherapy for breast cancer is well-appreciated clinically, little research has been conducted to investigate the underlying mechanisms of this energy imbalance. Appropriate interventions cannot be developed until this is known. The specific aims of the proposed research are as follows: 1) to quantitate changes in energy intake and specific components of energy expenditure (ie. resting metabolic rate, diet-induced thermogenesis and physical activity) in 100 premenopausal breast cancer patients receiving adjuvant chemotherapy [six month regimens of cyclophosphamide + methotrexate + 5 fluorouracil (CMF) or cyclophosphamide + doxarubacin + 5 fluorouracil (CAF)] and 2) to use the findings of this proposed research to develop an appropriate intervention to prevent weight gain in this population. This research avenue has the potential to increase both the quantity and quality of life for breast cancer patients undergoing adjuvant chemotherapy, while making an overall contribution to our understanding of body weight and cancer.